Spring retainer for bucket teeth



March 20, 1962 C. M. TOWNE ETAL SPRING RETAINER FOR BUCKET TEETH FiledMay 18, 1959 f7? Jezztar Claude /y. 75 Jzzlea A. 3rd

$325,619 Fat-eluted Mar. 29, l92

3,025,619 SPRIN G RETAINER FUR BUCKET TEETH Claude M. Towne,.Watertown,Wis and Jules L. Brady, Chicago, Ill., assignors to General MetalsCorporation, a corporation of Deiaware Filed May 18, 1959, Ser. No.813,904 8 Claims. (Cl. 37-142) This invention relates to earth diggingteeth such as may be used on buckets, angers, shovels or other heavyduty excavating or earth moving equipment. More specifically, theinvention has to do with the replaceable feature of a tooth cap and themeans for holding the cap on a base support.

Buckets and similar digging tools used on earth moving machinery areoften equipped with spaced teeth to loosen the soil, rock or othermaterial. The teeth take the brunt of impact, abrasion and wear.Ordinarily, steel is used as the material for the teeth and graduallywears away in use requiring replacement. The replaceable part of suchearth digging teeth should be held quite tightly to its supporting baseto promote the longest possible life. At the same time, the teeth shouldbe readily replaceable for the convenience of maintenance personnel. Theextreme conditions of use of such equipment is conducive to rapidwearing particularly should the teeth become loose so that it isimportant that they be retained tightly on the base at all times. Theretainer of the present invention provides a structure capable offulfilling all of the foregoing requirements.

It is therefore the primary object of this invention to provide a newand improved retainer for earth digging teeth.

Another feature is to provide a retainer of the character describedwhich by its structure is particularly simple to apply and remove,permitting ready change of new teeth for those that are worn.

A further feature is to provide a retainer of one-piece all metalconstruction which operates to hold the replaceable teeth caps tightlyon their base support under all operating conditions.

Other objects, features and advantages of the present invention will beapparent from the following description of a preferred embodimentillustrated in the accompanying drawings, in which:

FIGURE 1 is a fragmentary side elevational view partly in section of areplaceable tooth cap on a supporting base and having the retainer ofthe present invention therein;

FIGURE 2 is a fragmentary sectional view through the structure shown inFIGURE 1, taken substantially along line 22 therein;

FIGURE 3 is a transverse sectional view through the replaceable capstructure shown in FIGURE 1, taken substantially along line 3-3 therein,and

FIGURE 4 is a fragmentary perspective view of one end of the retainerillustrated in FIGURES 1 through 3.

The replaceable tooth point chosen to illustrate the invention istypically one used on an earth digging bucket of the type used withdraglines, hoes or trenching machinery. The digging bucket generally isprovided with a forward lip or cutting edge formed of an abrasionresistant material and having thereon spaced locations for the supportof digging teeth. In some instances, the supports are integrally formedwith the bucket lip referred to and in other instances, the support forthe tooth is a separate cast metal member. The separate tooth supportsare sometimes referred to as adapters.

In the drawings, an adapter or tooth support is illustrated, the adapterbeing a cast metal member 5 having an end for attachment to a bucket(neither shown). The

base supports for the teeth have generally a forward extending noseportion 6, terminating in a relatively narrow front portion 7 so thatthe nose forms a relatively wedge shaped projection at the front of thebase support. This nose portion is provided with a cross bore 8intermediate its ends but closer to the enlarged base than the narrowouter end 7. The cross bore is intended to serve as a menas by which thewear surface cap of the tooth is secured to the digging bucket.

The replaceable tooth is in the form of a cap adapted to fit over thewedge shaped nose portion of the supporting base referred to above. Thecap is provided with a relatively heavy top blade portion 10 formed of asteel selected for its particular ability to resist either impact orabrasion or both. The choice of the particular steel of which the blade10 is formed depends upon the service to which the particular earthmoving machinery is to be subjected.

The physical form of the replaceable cap blade 10 is generallyrectangular and elongated with an under sloping surface 11 providing theouter end 12 of relatively sharpened configuration as compared with theremainder of the tooth cap. The upper surface of the blade 10 is thesurface in contact with the material being dug and, therefore, receivesthe Wear resulting from the digging operation. A tongue 13 at therearward portion of the blade ltl is intended for reception within asocket 14 formed in the base support. The socket is somewhat larger thanthe tongue to insure the reception of the latter therein and yet ischosen to prevent undue movement of the replaceable cap relative to thebase.

The replaceable cap is provided with a housing adapted to fit on to theprojecting nose portion of the base support. Herein the housing of thereplaceable cap is formed of a carbon steel sheet or plate 15, so formedas to have a bottom wall 16 and a pair of sidewalls l7 and 18. The sheetis so formed that the upper edge 20 on the wall 17 may be welded to theunderside 21 of the heavy metal blade 10, forming'the upper side of thecap. The upper edge 22 of the wall 18 is likewise welded to theunderside of the blade 10. The lower wall 16 forming a part of thesocket is held at an angle to the underside of the blade 10 and isattached at its forward edge 23 to the underside of the blade 10 as bywelding 24. The carbon steel sheet 15 is subjected to very little wearas it is on the underside of the replaceable ca and the heavy blade 10receives the brunt of all impact and abrasion. The function of thehousing formed by the sheet 15 is to support the heavy blade ltl inproper position on the base support. The sides 17 and 18 have rear edges25 and 26 so positioned as to avoid contact with opposite shoulders 27and 23, formed on the base support 5. It is known that some movement ofthe replaceable cap on to the base support during use may occur and thecap edges should be spaced from the base support shoulders a sufficientdistance to permit such movement without interference.

In order to assure proper operation and maximum life or" a replaceabletooth cap, the cap should be retained tightly on the base support. Thereshould be no loose ness since the bucket teeth are often subjected toimpact and looseness may promote breakage. In the present structure aretainer is used which will always urge the cap on to the base support.Referring to the drawings, a spring steel pin 3% of generally roundconfiguration is bent intermediate its ends into the form of a wideangled V. The pin is shown in FIGURES l, 2 and 3 in the position whichit occupies, holding the cap on the base. In this position, it is sprungtoward straightness from its at rest position. A wedge surface 31 at oneend of the pin engages the side 17' of the cap within an opening 32therein. A similar Wedge surface 33 on the opposite end of the pinengages the side 18 of the cap in a similar opening 34 formed therein.The base 3.2 of the pin engages within the bore 8 of the adapter or basesupport. Since the pin is sprung in the position shown and the centralportion of the pin engages only the base support and the ends of the pinengage only the cap, the pin resiliently urges the cap upon the base. Itwill be noted that the bore in the base support is sufficiently large inthat direction of movement on to the base as to avoid any contact withthe ends of the pin.

The formation of the wedge surfaces referred to may best be seen inFXGURE 4. The wedge surface is cylindrical in nature and extends from aradial shoulder 36 cut into the stock from which the pin is made. Theshoulder is generally crescent shaped. The end surface 37 of the pin isalso radial to the pin stock. The wedge surface, in addition to beingcylindrical, is angled relative to the axis of the adjacent pin leg soas to extend thereacross and face the end of the pin. Each wedge surfaceis similarly formed and is produced by eccentrically supporting the pinstock and cutting the shoulder 36, wedge surface 31 and end surface 37while so supporting the stock.

The wedge surfaces and shoulders referred to are important in theoperation of the insertion and removal of the retainer pin. When a capis first placed on the nose of the base support, it may be manuallyshoved thereon to within about /8 of an inch of its final position. Atthis point, the side openings 32 and 34 will be generally aligned withthe cross bore 8. The pin is inserted manually until the end 37 engagesthe inside of the cap socket wall 17. By manipulation, the wedge surface3 should engage in the opening 32. At this point, the pin is notproperly seated, as the end 37 merely touches the opening 32 in the capwall 17 and the opposite end of the pin extends outwardly of the capopening The pin must be sprung to force the portion 38 of the pin pastthe opening 34. A blow of a hammer or a maul against the end 39 of thepin will cause it to spring and allow the pin to move into the alignedopenings so that the shoulder :it) passes through the opening 34,allowing the wedge surface 33 to engage in the opening. The Wedgesurface 31 or 33 will provide a \vedging means to spring the pin againstthe side openings in the cap allowing an endwise delivered blow tospring the pin in place. Once sprung in place, the shoulders 36 and 40keep the pin from accidentally moving out of the aligned openings andbore by engaging against the inner surface of the cap side walls.

The removal of the pin is accomplished by driving it lengthwise out ofposition shown in FIGURES 1, 2 and 3. The end of the pin can becontacted by a punch or short rod and by hitting the same with a hammer,the shoulder 36 on the opposite end will spring the pin further topermit it to be driven out. Since the shoulders 36 and 40 were formedradially to the pin stock, and thereafter the stock bent into the wideangled V shape, the shoulders end up at an acute angle to the inside ofthe cap side walls. This provides a wedge for springing the pin toremove it. The inside surfaces about the cap openings should be flamehardened to withstand the impact, and also to stand up during use of thetooth in digging operations.

The present pin is shown as round and in some instances, top and bottomflats may be provided to mate or match with corresponding hats in theside openings 32 and 34. It is possible to place the pin in the openingsturned 180 from its proper position. Under such circumstances, theworkman is immediately apprised of this error in that the pin, whendriven in, will not be tight but exceedingly loose. When properlypositioned, considerable force is necessary to insert the pin and it isexceedingly tight once inserted.

It is preferred to form the pin of a spring steel which is hardenedafter the wedge surfaces, shoulders and end surfaces are cut from thestock, A carbon and man- .t ganese steel is preferred which can be heattreated follow ing the cutting of the surfaces so as to stand up underthe conditions of usage. A Rockwell C Scale hardness of from 52 to 53has been found satisfactory, permitting a single retaining pin to beused to retain successive replacement caps on an earth digging basesupport. The flame hardening on the edges of the cap is preferably doneto an extent to produce a hardness greater than that of the pin so thatthe edges of the opening of the cap will not be damaged by the insertionor removal of the retaining pin.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, for some modifications will be obvious to those skilled inthe art.

We claim:

1. An earth digging replaceable tooth cap retainer for securing a caphaving aligned side openings upon a base having a cross bore,comprising: a spring steel elongated pin bent intermediate its endsforming a wide angle V to permit resilient yielding of the pin uponmovement of the legs thereof toward endwise alignment, a Wedge surfaceformed on each end of the pin for engaging the replaceable tooth capwithin said side openings permitting springing of the pin within theadapter bore by endwise insertion, and a shoulder on the pin at the baseof the wedge surface for retaining the pin Within the adapter boreagainst accidental removal, said pin resiliently urging the cap on saidbase when the pin is sprung in the cross bore and cap side openings withthe central pin portion engaging said bore and the ends of the pinengaging said cap.

2. An earth digging replaceable tooth retainer for securing a removablecap having aligned side openings upon a base having a cross bore,comprising: a spring metal pin having a cross-sectional shape and sizeto enter said side openings and cross bore freely, each end portion ofsaid pin having a flat end surface generally normal to the longitudinalextent of the adjacent pin portion, a shoulder extending inwardly fromthe periphery of the pin and positioned in spaced relation to said flatend surface and a cylindrical surface extending fromv the shoulder tosaid flat end surface with the cylindrical surface being angled relativeto the longitudinal extent of the adjacent pin portion, said pin beingbent cen trally to form a wide angle V with the outer base side of the Vfacing away from said angled cylindrical surfaces to permit the angledsurfaces to engage the removable tooth cap in said side openings and thebase of the pin to engage the base within said cross bore resilientlyurging the cap onto the base.

3. In an earth digging tooth having a replaceable cap with oppositealigned openings for register with a bore through a supporting base, aretainer for securing the replaceable cap on the base, comprising: anelongated steel spring pin bent intermediate its ends to form a pair oflegs arranged at a wide angle V in plan, means forming a shoulderadjacent each end of the pin on the interior side of the V, a wedgesurface extending from the base of each shoulder to the adjacent end ofsaid pin with said surface being oriented in a direction to extendacross the longitudinal extent of the adjacent pin leg at an anglethereto and face the adjacent end of said pin leg, said wedge surfacespermitting springing of the pin when driven endwise into said capopenings and base bore to bring the same into register, said shouldersbeing spaced to abut the inside of the cap about said openings to retainthe pin in said openings and bore and maintain the cap and baseassembled.

4. in an earth digging tooth as specified in claim 3 wherein saidshoulder is oriented substantially normal to the longitudinal extent ofthe adjacent pin leg so as to extend at an acute angle to the insidesurface of said cap about said opening permitting cannning of said pinshoulder into said opening upon forced endwise driving of the pin out ofthe aligned openings and bore.

5. In an earth digging tooth having a replaceable cap with oppositealigned openings for register with a bore through a supporting base, aretainer for securing the replaceable cap on the base, comprising: anelongated steel spring pin having its end portions offset relative toits central portion to permit resilient flexing of the pin between saidoffset relation and a position aligning said end portions and centralportion, a wedge surface on said pin at each end extending across andangled relative to the longitudinal extent of the adjacent pin portionand facing the adjacent end of the pin for engaging said cap opening tospring said pin into said openings and bore upon endwise driving of thepin therein, a shoulder at the inner end of each wedge surface forabutting the inner surface of the cap to retain said pinf within thealigned openings and bore, said shoulder extending at at angle to astraight line through said openings and bore and at an acute angle tothe interior surface of said cap about said opening to cam said pin pastthe cap opening when forceably driven endwise out of the cap and base.

6. An earth digging replaceable tooth cap retainer for securing a caphaving aligned side openings upon a base having a cross bore,comprising: an elongate one piece spring steel pin of generally roundconfiguration having a bend intermediate its ends forming the pin into aWide angle V-shape and permitting springing resiliently from saidV-shape toward straightness, a wedge surface at each end of the pin forengaging the cap in said side opening, with the intermediate portion ofsaid V-shape bearing against the base Within said cross bore so that theresiliency of the pin urges the cap onto the base, and shoulder meansintegral with the pin, one shoulder adjacent to and facing each end ofthe pin, said shoulder extending at an angle to a straight line throughsaid openings and bore and at an acute angle to the interior surface ofsaid cap about said opening to cam said pin past the cap opening whenforcibly driven endwise out of the cap and base.

7. In an earth digging tooth having a replaceable cap with alignedopenings for register with a bore through a supporting base, a retainerfor securing the replaceable cap on the base, comprising: a spring steelone-piece pin of elongate form having its end portions offset relativeto its central portion to permit resilient flexing of the pin betweensaid offset relation and a position aligning said end portions andcentral portion, said end portions having a reduced thickness portionwith a shoulder between said reduced thickness portion and the remainderof the pin, said shoulder facing the adjacent end of the pin, said pinbeing insertable endwise into said cap openings and supporting base borewith said end portions bearing only against said cap in opposition tosaid central portion bearing only against said base so that fiexure ofthe pin resiliently holds the cap on said base, said pin havinggenerally the same cross-sectional shape through the majority of itslength, and said shoulders being spaced apart on the pin to bepositioned between said cap openings so as to engage the interior of thecap about said openings retaining the pin in assembly with the cap andbase.

8. In an earth digging tooth having a replaceable cap with oppositealigned openings for register with a bore through a supporting base, aretainer for securing the replaceable cap on the base, comprising: anelongated steel spring pin having its end portions offset relative toits central portion to permit resilient flexing of the pin between saidofiset relation and a position aligning said end portions and centralportion, a wedge surface on said pin at each end extending across thelongitudinal extent of the adjacent pin portion and facing the adjacentend of the pin for engaging said cap opening and bore upon endwisedriving of the pin therein, said pin having a shoulder at the inner endof each wedge surface for retaining the pin in said openings and bore byengaging the inner surface of said cap about said openings.

References Cited in the file of this patent UNITED STATES PATENTS2,129,420 Guy Sept. 6, 1938 2,325,991 White Aug. 3, 1943 2,610,416Crawford Sept. 16, 1952 2,772,492 Murtaugh Dec. 4, 1956 2,860,520 SullNov. 18, 1958 2,936,538 Opsahl May 17, 1960 FOREIGN PATENTS 565,417Great Britain Nov. 9, 1944

